Tool for setting tubular rivets



March 26, 1968 A. E. Di MAIO 3, 74,656

TOOL FOR SETTING TUBULAR RIVETS A wm Filed Jan. 25, 1966 I5 Sheets-Sheetl I l i ATTORNEYS March 26, 1968 A. E. Dl MAIIO 3,374,656

TOOL FOR SETTING TUBULAR RIVETS Filed Jan. 25, 1966 3 Sheets-Sheet 2 Illllll! FIG.5

FIG.3

lllllHl INVENTOR.

ATTORNEYS March 26, 1968 501 MAIO 3,374,656

TOOL FOR SETTING TUBULAR RIVETS Filed Jan. 25, 1966 1 3 Sheets-Sheet 5 Lx AHW I;

FIG. 6

/se 84 i' 78 Al/ m 1 38 I Qx -82 e I A 1% W FIG. 7 INVENTOR. @lflxiaflnw BY Wama afi2 ATTORNEYS United States Patent 3,374,656 TOOL FORSETTING TUBULAR RIVETS Anthony E. Di Maio, Georgetown, Mass., assignorto Marson Fastener Corporation, Chelsea, Mass., a corporation ofMassachusetts Filed Jan. 25, 1966, Ser. No. 522,898 Claims. (Cl. 72-391)The present invention relates to fastener setting tools and, moreparticularly, to tools of the type adaptd to set a tubular rivet into anapertured structure that may be accessible from one side only. Such atubular rivet, for example, comprises: an external tubular member ofrelatively ductile material having a preformed flange at the rearwardend of the rivet; and an internal mandril member having a head engagingthe tubular member at the forward end of the rivet and a stem projectingthrough the rearward end. In operation, first the forward end of therivet is inserted through the aligned holes of a pair of workpieces tobe joined with the preformed flange abutting against the outer face ofone of the work pieces. Next the stem is gripped by a tool and retractedthrough the rearward end in such a way that the head deforms the tubularmember at the forward end of the rivet to provide a new formed flangeabutting against the outer face of the work pieces. Finally, continuedretraction of the mandril member, when the new formed flangesufficiently resists further movement, causes a rupture within thetubular member of an expendable portion of the mandril member from theremainder, thereby leaving the rivet set into position and free of thetool. The present invention contemplates a novel automatically operablerivet setting tool characterized by an arrangement by which certainmandril gripping elements are automatically actuated in a simple mannerby an unusually efficacious but compact power train.

The primary object of the present invention is to provide a rivetsetting tool comprising a mandril gripping and releasing collet, whichis actuated and de-actuated by a motor driven, hydraulic cylinder, theentire structure being within the format of a manually triggered gun. Ithas been found that the foregoing arrangement enables the promptapplication of power but the smooth avoidance of shock.

Other objects of the present invention will in part be obvious and willin part appear hereinafter.

The invention accordingly comprises the device involving the componentsand relationships exemplified in the following detailed disclosure, thescope of which will be indicated in the appended claims. For a fullerunderstanding of the nature and objects of the present invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings wherein:

FIGS. 1(a) and ([2) illustrate the operation of an exemplary rivet, forwhich the rivet tool of the present invention is designed;

FIG. 2 is a side view, with parts broken away, of a tool embodying thepresent invention, certain components being shown in one stage of ariveting cycle;

FIG. 3 is a front view of the tool of FIG. 2;

FIG. 4 is a view of certain components of the tool of FIG. 2 in anotherstage of the riveting cycle;

FIG. 5 is a rear view of the components of FIG. 4;

FIG. 6 is a schematic detail view of a component of the tool of F IG. 1in a first position; and

FIG. 7 is a detail view of the component of FIG. 6 in a second position.

A typical rivet for use with the tool of the present invention is shownat 10 for use in connecting a pair of work pieces 11, 12 that areapertured at 13 by aligned holes. The rivet is shown as including amandril 14 surrounded 3,374,656 Patented Mar. 26, 1968 by a tube 15.Tube 15 is composed of a relatively soft metal such as soft steel andmandril 14 is composed of a relatively hard metal such as hard steel.Mandril 14 is provided at one extremity with a head 16 that abutsagainst the forward part of tube 15 and is provided at the otherextremity with a stem 17 that extends rearwardly from tube 15. Stem 17is separated from head 16 by a constriction 18, which constitutes aweakened point at which the mandril ruptures when a predeterminedtensile force is exceeded. As shown in FIG. 1(b), after tube 15 isinserted through aperture 13 in such a way that the flanged portion 19of tube 15 abuts against the Work pieces, mandril 17 when withdrawn,effects a deformation of the head extremity of tube 15 in order toprovide a flange 21 which cooperates with flange 19 in order to grip thework pieces therebetween.

The general assembly of the illustrated tool is shown in FIG. 2 ascomprising a housing generally in the form of a gun, a collet 32 forgripping, retracting and releasing the mandril of a rivet of the abovedescribed type, a motor 34 that is actuated by a trigger 36 to operate ahydraulic cylinder 38 and a linkage 40 by which the cylinder isoperatively connected tocollet 32.

Housing 30 has a forward nose portion 42 to which collet 32 is affixed,a manually grippable handle portion 44 in which hydraulic cylinder 38 islocated, and a rearwardly projecting casing portion 46 in which electricmotor 34 is located. Rearward casing 46 has at its rearward extremity aplurality of slots 48 by which motor 34 is air cooled.

' Collet 32 includes a mounting shell 50, the rearward extremity ofwhich is shouldered and threaded into a corresponding opening in noseportion 42 of the housing. Slidable Within shell 50 is a reciprocablecollet case 52 the forward end of which is open as at 54 and therearward end of which provides a bearing 56. Within collet case 52 is acollet 58 and a spring, not shown, which resiliently presses collet 58outwardly through opening 54. Collet 58 includes a pair of jaws 62, 64which are spread by an anvil 66 into open condition when the collet init is in its foremost position. Anvil 66 is the rearwardly projectingtubular extremity of a head 68 through which the mandril of a rivet ofthe foregoing type is inserted prior to the riveting cycle. The rearwardend of tubular extremity 66 is tapered so as to wedge the taperedextremities of the spring jaw 62, 64 of collet 58 into open positionwhen in contact therewith. When the collet is removed to its rearwardposition, collet 58 is urged forwardly by spring within collet case 52,which is shaped to urge jaws 62, 64 together, thereby gripping themandril with which they are contiguous.

The forward and rearward motion of collet 32 is under the control of afollower 66 within bearing 56. Follower 66 constitutes the extremity ofa rocker arm 68, which is pivoted in the nose portion of housing at 70and which has a crank arm 72. Crank arm 72 is pivoted to one extremityof a link 74, the other extremity of which is controlled by hydrauliccylinder 38. As shown in FIGS. 6 and 7, hydraulic cylinder 38 includes acylinder portion 76 which presents cylinder chambers 78, 80 at itsopposite extremities. Reciprocable within cylinder portion 76 is apiston portion 82, the opposite extremities of which project intocylinders 78, 80. Afiixed to the walls of chambers 78, 80 and to thefaces of cylinder 82 are a pair of elastomeric diaphrams 84, 86,composed for example of neoprene, which conveniently seal chambers 78,80. Projecting into the ports 88, of chambers 78, 80 are tubes 92, 94which communicate with the opposite mouths of a hydraulic pump 96.Hydraulic pump 96, when powered in actuating direction by motor 34,drives hydraulic cylinder piston 82 upwardly and when powered inde-actuating direction by motor 34 drives hydraulic cylinder piston 82downwardly. A suitablehydraulic fluid, for example, a hydrocarbon oil,fills the cylinders, conduits and pump. Motor 34 contains a simplecontrol which rotates the motor in the actuating direction whenenergized by the trigger 36 and which rotates the motor in tie-actuatingdirection when trigger 36 is released.

a In operation, first the mandril of a rivet of the foregoing type isinserted through anvil 66 into collet 32 at the beginning of a cyclewith collet 32 in its foremost position. Thereafter the tubular portionof the rivet is inserted through the aligned openings of a pair of workpieces to be assembled. Next trigger 36 is squeezed while the gun isheld in the hand of an operator. Actuation of trigger 36 causes motor 34to power pump 96 and to cause the fluid in the system to flow fromchamber 80 to chamber 78 thereby causing piston 82 to move downwardlyand causing collet 32 to move rcarwardly by the action of linkage 40.Next, the rearward part of the mandril is separated from the forwardpart of the mandril at the constriction in the mandril followingdeformation of the rivet as in FIG. 1(b). Release of trigger 36 causesreverse rotation of motor 34 and pump 96, by which the hydraulic fluidflows from chamber 78 to chamber 80, thereby completing the rivetingcycle.

The present invention thus provides an extremely convenient and shockfree rivet setting tool characterized by a particular arrangement ofelectric and hydraulic components. Since certain changes may be made inthe device hereof without departing from the scope of the presentinvention, it is intended that all matter described in the foregoingspecification or shown in the accompanying drawing be interpreted in anillustrative and not in a limiting sense.

What is claimed is:

1. A tool for setting tubular rivets of the type having an outer barrelportion and an inner mandril portion, said outer barrel portion having arearward flange, said mandril portion having a head at the forward endof said outer barrel portion and a stem extending rearwardly ciprocablein said collet case between a forward position and a rearward position,said collet when in said forward position being open to receive saidstem and when in said rearward position being closed to retract saidstem, said hydraulic cylinder being operatively connected to said colletcase.

2. The tool of claim 1 wherein said cylinder is positioned in said gripportion and said motor is positioned substantially between said gn'pportion and said nose portion.

3. The tool of claim 1 wherein said hydraulic cylinder means providestwo compartments and a piston therebetween, said hydraulic pump forcingsaid hydraulic fluid through conduits from one compartment to the otherwhen said motor is actuated.

4. The tool of claim 1 wherein a linkage connects said hydrauliccylinder to said collet.

5. The tool of claim 1 wherein said compartments are defined in part byelastomeric diaphrams connected to said cylinder.

References Cited UNITED STATES PATENTS 2,343,278 3/1944 Cherry 7245s2,679,727 6/1954 McLeod 6052 3,082,898 3/1963 Bosch 72 391 FOREIGNPATENTS 161,914 8/1933 Switzerland. RICHARD J. HERBST, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

1. A TOOL FOR SETTING TUBULAR RIVETS OF THE TYPE HAVING AN OUTER BARRELPORTION AND AN INNER MANDRIL PORTION, SAID OUTER BARREL PORTION HAVING AREARWARD FLANGE, SAID MANDRIL PORTION HAVING A HEAD AT THE FORWARD ENDOF SAID OUTER BARREL PORTION AND A STEM EXTENDING REARWARDLY FROM SAIDHEAD AND FROM SAID OUTER BARREL PORTION, SAID TOOL COMPRISING A HOUSINGHAVING A NOSE PORTION AND A GRIP PORTION, A COLLECT CASE AFFIXED TO SAIDNOSE PORTION, AN ELECTRIC MOTOR IN SAID HOUSING, A HYDRAULIC PUMPOPERATIVELY CONNECTED TO SAID ELECTRIC MOTOR, HYDRAULIC CYLINDER MEANSCOMMUNICATING WITH SAID HYDRAULIC PUMP, A COLLET RECIPROCABLE IN SAIDCOLLET CASE BETWEEN A FORWARD POSITION